The Crater Lake at Poás Volcano changed from its characteristic turquoise color to a very peculiar shade of green. It is the first time scientist have seen this in almost two centuries of observation. The famous lake measures about 340 meters in diameter.
According to the National Seismological Network (RSN) the lake has already shown a wide range of colors similar to turquoise and mustard, or very clear, similar to white, but never that shade of green that has been seen in the Crater Lake at Irazú Volcano.
The park rangers and volcanologists are amazed and keep following these changes in nature. There is a very active underwater fumarole mouth that injects a lot of sulfur dioxide, so the visible light of blue combines with the yellow of the sulfur and possibly generates that peculiar color for the Póas,”
reported geochemist María Martínez, from the Volcanological Observatory and Seismological of Costa Rica (OVSICORI).
For more than a year, the authorities closed Poás Volcano National Park due to strong eruptions. Its reopening began gradually in August.
According to data from the National System of Conservation Areas (SINAC), Poás is the second most visited national park just behind Manuel Antonio.